[A/S] Jim R's offroading questions

[estatewagons@xxxxxxx]

> Can a late model Airstream be properly raised for GENTLY modest offroad use? 
> I am intrigued by the monocoque aspect of the Airstream trailer and its 
> durability if towed "properly" over rough terrain. 
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Jim - in response to your request for input - here are a couple of thoughts to 
consider - please keep in mind I am not an engineer - just trying to visualize 
this as best I can  from the perspective of a fellow trailer hobbyist - and 
offer a few suggestions to consider and possibly look further into.

The Airstream of today is not a full monocoque design.  It's a partial 
monocoque.  I don't know if it really makes a difference for what you are 
considering - but it might so keep it in mind.  The trailer sits on an actual 
frame - but then the whole rig is tied together - so that it needs the whole 
design to stay together.   

One thing comes to mind - with a standard Airstream - the hitch is more-or-less 
in a flat plane with the axles.  I believe the trailer wants to be towed as 
level as possible - this seems to be what is suggested by Airstream and the 
professionals who know all about hitch/towing geometry etc.  If there is a 
difference in height between the trailer tongue and the towing vehicle - the 
difference is usually made up by the extension on the hitch (up or down)  So - 
the pulling force is more or less a straight plane from the ball to the tongue 
of the trailer and then back to the axles.  Again - more-or-less.

Here is where I am wondering if a raised Airstream might cause concerns for the 
engineering department:

(a) If you raise the trailer and the axles and the tongue stay at their 
original height in relation to the road surface - then you'll have to add 
height extensions on the tongue and on the axles to allow for the extra ride 
height of the (level) trailer body.  That means the "pull would go from the tow 
vehicle to the hitch - then up - and then through the trailer - then down to 
the axles.

(b) If you raise the trailer and keep the tongue stock - and tow the trailer 
body level -  that means you'll be connecting to the hitch on your tow vehicle 
at a higher height - (say in the case of a jacked up 4X4) - then the "pull" 
from the hitch to the tongue will go through the trailer as designed - but 
then it will have to go "down" to the axles.

Somehow in my mind I would wonder if the direction of those altered towing 
forces would be hard on the Airstream?

Furthermore - since a modern Airstream has the dura-torque style axles - and 
not leaf springs - the attachment points are quite different - and somewhere in 
that arena....I think you might encounter more problems - especially with 
sway???

The higher up the body goes - might it allow for the up-and-down flexing of the 
body to be exaggerated as you go over bumps etc?

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> I know the Airstream went to war in WWII. That wasn't exactly "good 
> interior gravel roads" as the latest campground guide likes to put it. 
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There is lots of discussion regarding Airstream history these days - and to my 
knowledge - the WWII era is still one of the "mysteries" - it has been said 
that Wally Byam could not get the materials needed for building metal trailers 
during WWII - so he went to work for other people during that time.

If you know of any history about the Airstreams during WWII - it would be 
interesting to know.

It's about 1938 where the trail goes cold on Airstreams - and then it starts 
up in about 1946.

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> Can a late model Airstream be properly raised for GENTLY modest offroad use? 
>-------------------------------------------------------------------------------
Jim - I hope this info is of some help - again as I mentioned - don't go by 
this officially as I'm not an engineer - but hopefully it will give you some 
thoughts if you decide to talk to an engineer about this - or maybe it will 
catch someone elses attention - and they'll pipe in with whether I'm thinking 
off in the wrong direction.

Best Wishes.  RL McFarland
Seattle